Facile synthesis and properties of new (4-substituted-phehyl)azo-pyrido[2',3':4,5]thieno[2,3-d]pyrimidin-6-(5H)-one dyes derived from thioxopyrimidine

The new intermediate 4-hydroxy-9-methyl-2-oxo-7-phenyl-2(1h)-pyrido-[2',3': 4,5]thieno[2,3-d]pyrimidine has been synthesized in a simple single step from thioxopyrimidine. six novel (4-substituted-phehyl)azo-pyrido[2',3':4,5]thieno[2,3-d]pyrimidin-6-(5h)-one dyes were also obtained by coupled 4-hydroxy-9-methyl- 2-oxo-7-phenyl-2(1h)-pyrido[2',3':4,5]thieno[2,3-d]pyrimidine with appropriate diazotized arylamines. the dyes were applied to polyester and polyamide fibers as disperse dyes for creating hues ranging from orange-yellow to orange-red.the absorption spectral characteristics were correlated with substituted of dyes and solvent polarity. the results indicate that the introduction electron-donating group (och3) into the diazonium component resultsin hypsochromic shifts in dmf while they result in bathochromic shifts in thf. their fastness properties and color assessment are also discussed.